The objectives of the study were to evaluate the effects of timing of supplementation of different calcium salts of fatty acids on metabolic status, uterine health, pregnancy, pregnancy losses after two breedings and milk yield.

In the trial 1380 Holstein cows were randomly assigned to be fed either calcium salts of palm oil or safflower oil from 30 days prepartum through 30 days after calving. Animals were then further randomized to receive either calcium salts of palm oil or fish oil from 30 to 160 days postpartum. Supplementation of calcium salts of fatty acids was at 1.5 percent dry matter. At 43 days postpartum, cows were enrolled into a synchronization program and resynched if called open at 32 days after A.I. Cows diagnosed pregnant after both services were reexamined at 60 days of pregnancy to determine pregnancy losses.

The research team from the University of Florida reported the following results in the January 2011 issue of the Journal of Dairy Science:

•

Plasma PGF2α metabolite was greater in safflower-oil-fed cows at four and seven days postpartum.

•

Conception rates at day 32 and 60 after first breeding were not affected by diets, but pregnancy loss was less in cows fed fish oils.

•

At second breeding, pregnancy was greater in fish-oil-fed cows at 32 days and, at 60 days after breeding, was greater in cows fed safflower oil followed by fish oil.

•

Pregnancy loss after second breeding was not affected by diets.

•

Overall conception rates were greater in cows fed safflower oil followed by fish oil at 60 days of pregnancy and pregnancy loss was reduced in fish-oil-fed cows.